Improvement in burning bones for the manufacture of acid phosphates



2 Sheets-Sheet 1.

G. P. WILSON. BURNING BONES FOR THE MANUFACTURE OF ACID PHOSPHATES.

No. 75,332. Patented Mar. 10, 1868 WITNESSES.

- 2 Sh eets-8heet 2. v F. WILSON. BURNING 'BONES FOR THE MANUFACTURE OF ACID PHOSPHAT'BS.

No. 75,332. Patented Mar. 10, 1868.

I I i I 1' a w J WITNESSES.

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GEORGE F. WILSON, OF EAST PROVIDENCE, RHODE ISLAND.

Letters Patent iZVb.'.75,332, dated March 10, 1868.

IMPROVEMENT .IN BURNING Bones Pun THE MANUFAGTURE or AGID PHOSBHATES.

TO ALL- WHOM IT MAY CONCERN:

Be it known that I, GEOR-GE-F. WILSOR, of East Providence, in the'county of'Providence, and State of Rhode Island, have invented a new and improved Method of Burning Bones to' whiteness for use in the Pro- .duction of Horsfords Acid Phosphates for Culinary Uses: and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, and to the letters ofrcferen ce marked thereon.

- The object of my invention is to obtain bones burned to whiteness. To attain this object it is necessary that there be continuous intense heat and ready access of air. When I first began to make Hcrsfords pulverulent ac'idpl os'phates, I burned the bones in what is called a. reverberatory furnace, the ordinary form of fur. nace described in standard works. My'object then was to consume all the organic constituents of the bone, and to obtain a purely white phosphate of lime, to be employed as described in Horsfords patent. Without the expenditurejof large quantities of fuel, and the employment of expensive and skilled laborers, I found that I succeeded but imperfectly in the attainmentof my object, and even under these conditions the result was far from satisfactory: With the plans for leaching which I then followed, it was necessary that the bones should be burned as nearly white as possible, an indication that'all the organic elements had been consumed. It sulphur andcyanogen compounds and protoxide of iron, as.such,.were leftuin but. small quantities in the burned bones,ith e phosphoric acid leached fromthem was discolored and impure.

I foundthe ordinsry-reverberatory furnace objectionable in many respects.

First. It was expensive to keep it in operation. 7 I

Second. The products of'the combustion or burning of the .bones escaped into the atmosphere in large quantities, and were ofl'ensive to theneighborhood.

Third. If the bones were left on the sole of the furnace without frequent stirring, they wouldremaiu unburned. If they werefreqnently stirred, so as to bring them into contact with the air to whiten them, the furnace'would cool of, and'the whole mess would assume a grayish white tint, which ltwou'ld be diflicult after wards toremo've r Fourth. If the'furnsce were driven to a great heat, so as to whiten the whole mass, thensomo portions of the bone would be converted intosn'insoluble pyrophosphate of lime, of little or no value, and thus a loss I museu i To burn bones as nearly white as desired, and in a large way, for the manufactured Horsford's acid phosphotos, I discovered that. it was necessary that they should -be subjected to a steady, long-continued, uniform heat,'with 'suflicient air to secure perfect combustion without danger of cooling off the furnacefand-that it was desirable toattain the'se resultsand consume the greater part of the smoke atthe same time.

These ends are .gnined by'he employment of a furnace of particular shape and construction, and of sufli cientwinterior capacityfor the ready mixing of an adequate measure of air with the gases distilled from the bones, before thaQgases-leave the space wheretho heat of the combustion can reach the bones. without the heat arisingfrom the burning ofthe gases which the bones yield, it would be quite impracticable to obtain the necessary whiteness whereany considerable-quantity of bones is tobe handled at one time.

The accompanying din grams exhibit the form and constructionand arrangement of fines which I have invented, and which have been found to meet the wants of the case.

Figure 1 presents a vertical section, parallel to the front face of' the furnace.

Figure 2 presents a section at right angles to that shown in fig. 1, and exhibits its flu'es'ancl fire-space under the floor or sole of the furnace, and over the arch'ed'roofi-of the furnace.

Eigure 3 presents a ground plan, showing the fire-grateand the arrangement of fire-passages under the solei v Figure 4 exhibits the fines over thezarched roof of the furnace.

S isthe sole, offire-brick. o o o o is the arched roof of the furnace, with the intervening spaces for flues'i F F F' F" are the channels through which the heated products of combustion traverse the spaces over the arched roof, and by which they are conducted tolthe chimney. F F arethe openings, through which the flame from the grate A, having traversed the fines d see, tinderthe sole, enter" the furnace-chamber from the upright fl ues e"e(. G is the exit-flue over the furnsce-chamber, extending to thechimney-flue H. d -:c-are -passages,

which allow the fl ames'nnd products of combustion to pass from'the front of the furnace-chamber upwards into the fines -F' F, over said chamber,- andout through into the chimney H. Dis asliding damper in the childney H. K is the ash-pit," and may have a. water-trough, W, underneath.

The mode of operation is the following: After the 'furnace 'has' been thoroughly heated, s'hin-'bones,-jaws,

knnckle-hones, or sknlls oi' beeves, (each class itself,) are spread overthe sole or floor of the full-noes. The water is at once dri"en' out from the bones by the hentnand the fatty and animal motters begin to v a-po'rize; Air is admitted in quantitysnfiicicnt to insure ,the complete'combustion of the carbon; When this is done no black smoke issues from the furnace. If an excess of air is admitted it will chill the hones,1-andthi1s prevent their becoming white Theadmissionof air is regulated by raising or lowering the dooriB, and opening or closing the damper DL The flame fromthe fire-boxQafter trsversingjthe' fines e e e e under the sole .S, and

rising through the vertical flues e e, enters thefurnace-chember at- F F. Here it meets'the gases escaping from the bones, and the air from without, and mingling ivith them, and burning the gases, basses up through opertnres a: a: into F F, and G at length escapes 'throughthe' chimney Hi i I I It is indispensable that the temperature at which the distillation goes forward be not for once in'termitted, since, in the event of the heat of the bones falling below a certain high point, it is impossible, with nnjpractil' cable heat thereafter, to-burn them white. -With the aid of 'a. long spatula-the bones are-from time to time turned over, so as to facilitatetlreaocess of the air. The Hot bones like the jaws, and the round bon'e's, like the shins {require unequal times forburning White, andfor this reason, as indicated shore, it is better to burn each cls-ss by itself. When the honesnre wholly white theyorewithdrmwn into ironieoeptacles, and theirploce immediately supplied with fresh bones. When a charge is takenont and renewed, the damper is closed, to retard the heat (hiring the process of renewal. I

I'cloim, and desire to secure by Letters Patent ofgthe United Stntes-'- 1. The new and improved furnace, substantially as above describ'ed, whereby the flsme is carried under the hearth thereof, and is introduced into' the chamber which contains thegbones, where it burns with the combustible'prodncts ofldistillation and atmospheric air, admitted in regulated qnentitiesyan'd "thus, whilejhe offensive odors zi're destroyed, the heat of the chamber is intensified to the degree required for the production of white-burned bone, without converting the same into an :insolublepyrophosphate of lime; theflnmesnd products of combustion then passing into the fines-over the chamber into the escape-flue.

The'new and improved process of burning bones white, whereby'lmm enshled to obtain from them a. pure phosphate of lime, in the manner and for the p'urpose above specified.

' GEO. F. WILSON.

Witnesses:

WILL IAM HEDGE, W. H. MOGRENERY. 

